Doosan DA40 - Page 762

SHOP MANUAL
Ch 6 page 52
ELECTRICAL SYSTEM
Charge testing
The alternator must not be run without the battery connected.
The rectifiers can otherwise overload and be damaged.
Output test
1 Connect a calibrated test instrument with load resistor as
illustrated.
2 Start the engine and let it run for a few minutes before
carrying out the test.
3 Rev up the engine to 1715 rpm, 6000 rpm for the alternator.
Apply current to the load resistor.
The voltmeter should read 28 V.
The alternator must supply at least 88 A for the
90 A alternator.
A digital clip-on ammeter can be connected to
B+ on the alternator for a more precise reading.
1
Test instrument for alternator. Equipped
with voltmeter and ammeter plus
load resistor.
2 Connection to load resistor
3 Clip for current reading
4 Connection to voltmeter
5 Alternator
6 Starter motor
7 Battery
Control voltage test
This test requires fully charged batteries in
order to obtain correct readings.
1 Connect the voltmeter and ammeter as
illustrated.
2 Start the engine and allow it to run until the
alternator delivers 5 A at B+.
3 Rev up the engine to 1715 rpm, 6000 rpm
for the alternator.
Voltage at 20°C must be 28.0 V +0.5 V.
Equipped with voltmeter and ammeter
plus load resistor.
2 Connection to load resistor
3 Clip for current reading
4 Connection to voltmeter
5 Alternator
6 Starter motor
7 Battery
2
3
4
5
6
7
1
D+
W
B
B+
V
A
2
3
4
5
6
7
1
D+
W
B
B+
V
A
Figure 30
Figure 31